The constitutive relationship of elevated temperature creep of 40Cr steel

The creep behaviors of 40Cr steel were investigated at various temperatures and stresses. And the creep curves based on the experimental datas were plotted. It can be observed that the steady creep and the accelerating creep processes are the dominant parts of the creep curves of the 40Cr steel in the experimental conditions. Besides, the steady creep rates can be described by the Norton-Power law and the creep data can be fitted by the Monkman-Grant relationship. Then, a nonlinear constitutive equation for the 40Cr steel was proposed according to the experimental data. The parameters of the equation were determined by the least square method. At last, it can be found that the proposed equation can describe the creep behaviors of the 40Cr steel quite well by comparing the theoretical results calculated by the proposed equation and the experimental data.